Put Gold blocks in a 3x3 square. Put a hole in the middle. Put Mossy Cobble in the hole. Over the mossy cobble, put Nether Rack. Around the Nether Rack, put Redstone Torches. Take a flint&steel and light a fire in the Nether Rack. Herobrine will appear in the fire and wreck havoc on your world! Such as lighting your house on fire, destroying your chests, and lighting TNT! Hopefully he'll only pay you a little visit!